A method of performing functional analysis by checking tissue dynamics accompanying respiratory motion using a medical image generator such as an X-ray computed tomography apparatus (CT), a magnetic resonance imaging apparatus (MRI), or the like is very effective from the viewpoint of disease diagnosis and early diagnosis. Recently, a technique of repeatedly acquiring volume images covering an entire target tissue and performing multiplanar reconstruction (MPR) or three-dimensional moving image display has been generally used. When observing the lung fields, in particular, it is often a case that a target slice is designated by an MPR image, and its dynamics are observed.
A series of medical images constituting a moving image are chronologically arranged in the order of imaging and repeatedly reproduced. In lung field imaging, it is difficult to perform scanning throughout the entire period of one respiratory cycle because the respiratory cycle is long and there are demands for reduction in radiation exposure. For this reason, scanning is often executed while its period is shorted to a period almost corresponding to a half cycle of respiration. In this case, it is not possible to interpret a tumor or the like throughout the period of one respiratory cycle.
In some cases, a moving image is repeatedly reproduced. In this case, since respiratory phases are distant from each other between the final frame and first frame of the moving image, the visual continuity of the moving image breaks off.